Hello,
I don't know if you have the solution but mine seems related to the hdparm
option.
the -u option deals with irq and some distro disable it for maximum
compatibility.. and avoid filesystem corruption.
hdparm is difficult to set, but may be it can help
I do:
/sbin/hdparm -c 3 -d 1 -m 16 -A1 -u1 /dev/hda
But read the man page because it can kill your filesystem :) you are warned.
I hope it helps
Linium